This invention relates to shelf hanging clips, and more particularly, to shelf hanging clips for mounting shelves on vertical columns of storage rack systems.
Storage rack systems are designed to provide for the storage of items either on storage pallets placed on the racks, or on one of a variety of types of shelves mounted between vertical columns of the storage racks. When items are to be stored on shelves, many types of mechanisms are used to hang the shelves between the vertical columns of the racks. Some of these shelf hanging mechanisms are fastened to the vertical columns through the use of nuts and bolts installed through shelf adjustment holes on the sides of the columns. While nuts and bolts work well as fasteners, they are inconvenient to install and lengthen the time required for installation for shelves while nuts are being tightened onto the bolts.
Numerous types of single case shelf hanging clips and brackets had been devised which have hooks or tabs to connect to vertical rack columns, rather than use nuts and bolts to do so. These hooks or tabs on the shelf hanging clips typically fit into adjacent shelf adjustment holes in the vertical columns to latch onto the columns and support shelves on which items are to be stored. Typical shelf hanging clips and brackets of this type are shown in U.S. Pat. Nos. 4,180,003 Clement, 4,348,001 Baldwin, and Des. 392,551 Brady, et al.
One use of these shelf hanging clips and brackets is to support inclined gravity flow shelves which are installed on storage racks to be used for an order picking system. The inclined shelves often include tracks of rollers which enable cartons being stored to flow to the lower ends of the shelves as other cartons are removed.
Typically, shelf adjustment holes in vertical rack columns are spaced two or three inches apart. It is often desirable to give the shelf installers the option to make adjustments of less than two inches in the height of an end of shelves to adjust the angle of incline of inclined shelves being installed. Using vertical columns having shelf adjustment holes with two-inch spacing by way of illustration, shelf installers may need the flexibility of mounting shelves even with the shelf adjusting holes or one-half inch, one inch or one and one-half inches above these holes.
Shelf hanging mechanisms using nuts and bolts can make these adjustments by having a series of holes at various heights in them through which bolts can be inserted. The height at which a shelf or one end of a shelf is installed can be adjusted by changing the holes into which installation bolts are inserted in the shelf hanging mechanisms. Shelf hanging clips and brackets not using nuts and bolts to attach to rack columns normally cannot make small adjustments in the position at which they are mounted.
A universal hanger bracket shown in U.S. Pat. Des. 392,551 Brady, et al partially solves the need for a clip or bracket having flexibility in adjusting the incline of inclined shelves. A hanger bracket 20 depicted in the Brady, et al patent is show n in FIG. 1. The hanger bracket 20 is U-shaped so that it is made up of three rectangular metallic plate sections consisting of end section 22, middle section 24, and end section 26. Each of these rectangular sections 22, 24, and 26 is joined to an adjacent rectangular section at a corner due to the bending of the plate during the manufacture of the U-shaped hanger bracket 20. Thus, the rectangular section 22 is connected through the corner 28 to the rectangular section 24. The rectangular 24, itself, is connected through a corner 30 to the rectangular section 26.
Each of the rectangular sections 22 and 26 has a pair of tabs punched out of the plate which makes up these sections so as to extend through the outside surface of the U-shaped hanger bracket 20. Thus, tabs 32 and 34 extend from an outside surface 35 of the rectangular section 22, and tabs 36 and 38 extend from an outside surface 39, only an edge of which is shown in FIG. 1, of the rectangular section 26 of the U-shaped hanger bracket 20. Each of the tabs is hook-like in shape, with the ends of tabs 32 and 34 and the ends of the tabs 36 and 38 all extending in one vertically downward direction, as shown in FIG. 1. The rectangular section 24 has a notch 40 shown in FIG. 1, its upper end which is proximate to tabs 32 and 36. The purpose of the notch 40 is to receive and retain the bottom of one side of a shelf being supported by the hanger bracket 20 on bottom surface 42 of the notch 40.
As explained above, the set of tabs 32 and 34 and the set of tabs 36 and 38 are designed to fit into vertically adjacent holes in a vertical rack column to latch the U-shaped hanger bracket 20 onto the column to enable it to support a shelf. Each of the tabs has a bearing surface, which is the flat, upper portion of the underside of the hook-like structure of the tab. The bearing surface contacts the bottom of a shelf adjustment hole into which the tab is inserted. Thus, tab 32 has a bearing surface 44, tab 34 has a bearing surface 46, tab 36 has a bearing surface 48, and tab 38 has a bearing surface 50. The tabs 32 and 34 are spaced apart at a distance equal to the distance between the adjacent shelf adjustment holes in the vertical rack columns, as are the tabs 36 and 38. The tabs 32, 34, 36 and 38 all have a size which enables them to fit through the shelf adjustment holes and around the steel plate out of which the columns are manufactured. As a result the bearing surfaces 44 and 46 contact the bottom of shelf adjustment holes when the tabs 34 and 36, respectively, are inserted into the holes, and the bearing surfaces 48 and 50 contact the bottom of shelf adjustment holes when the tabs 36 and 38, respectively, are inserted into the holes.
As shown in FIG. 1, the bearing surface 44 of the tab 32 is at about the same height on rectangular section 22 as the bottom surface 42 is on rectangular section 24. The bearing surface 46 of the tab 34 is, thus, a distance below the bottom surface 42 equal to the distance between adjacent shelf adjustment holes in the vertical column in which the hangar bracket 20 is to be mounted. As a result, when the tabs 32 and 34 are used to latch the hanger bracket 20 onto a vertical rack column, the bottom surface 42 of the notch 40, which supports a shelf, is at the height of the shelf adjustment hole through which the tab 32 extends. The tab 34 assists in supporting the hanger bracket by latching onto a shelf adjustment hole below the hole through which the tab 32 extends.
The bearing surface 48 of the tab 36, on the other hand, is a preselected distance below the bottom surface 42 of the notch 40. Thus, the bearing surface 50 of the tab 38 is below the bottom surface 42 of the notch 40 by a distance equal to the preselected distance, plus the distance between the shelf adjustment holes into which the tabs 36 and 38 are to be inserted. For this reason, when the tabs 36 and 38 are used to latch the hanger bracket 20 onto a vertical column of a rack system, the bottom surface 42 is the preselected distance above the shelf adjustment hole in which tab 36 is mounted.
As a result of the structure described above, the U-shaped hanger bracket 20 can hold a shelf within the notch 40 at either of two levels: At the level of the shelf adjustment hole in which the tab 32 is mounted, or at a predetermined level above that hole when the tab 36 is mounted in it. While the U-shaped hanger bracket 20 provides two heights at which shelves can be mounted within a particular shelf adjustment hole, there are shelf installations when additional adjustments are needed. Prior to this invention the only way to obtain additional height adjustments was to provide shelf installers with separate hanger brackets having tabs set at different distances from the bottom surface of the notches at the tops of these brackets.